Top-mounted vehicle rack systems provide a versatile platform for transporting bicycles, skis, snowboards, boats, cargo boxes, gear racks, and/or other items. Such rack systems typically use pairs of crossbars that extend side-to-side across the top of a vehicle. Each crossbar is typically supported on each side of the vehicle's roof by a tower, where the length of each crossbar and the distance between crossbars depend on factors such as the shape and size of the vehicle's roof, and type(s) of cargo being carried. The towers supporting the rack crossbars are securely fastened to the vehicle in a suitable manner.
Various article carriers are designed for mounting on a set of crossbars, and to carry a variety of articles such as bicycles, skis, snowboards, and/or boats. For example, clamp devices are used to secure skis and snowboards in a scissor-like fashion. However, some clamp devices have problems such as; failing to fit or adapt to certain vehicle or factory rack configurations; failing to accommodate skis or snowboards with bulky bindings or attachments; and unsatisfactory adjustability to secure equipment of different shapes and thicknesses. Moreover, article carriers mounted on vehicle roof tops typically increase the height profile of the vehicle. Increased front facing profile or surface area may cause wind resistance related problems, such as increased driving noise, reduced fuel efficiency, etc. Users may remove the article carriers when not in use to avoid or minimize such problems. However, removing the article carriers between uses may not be convenient or desirable.